Why choose our manual breast milk pump? 1.Manual breast milk pump uses innovative two-phase technology to conveniently and comfortably express breast milk. 2.The handle of the pump adjusts to easily switch between Stimulation and Expression phases. The Stimulation phase allows more rapid suction, similar to baby’s suction pattern at the beginning of a breastfeed, to elicit a letdown. Once milk starts flowing, it’s easy to switch to the Expression phase which provides slower cycles with more suction to efficiently express breast milk.